Accession Number:

AD0760690

Title:

Approximate Array Gain Expressions for Vertically Directive Noise.

Descriptive Note:

Research and development rept. Jul-Nov 72,

Corporate Author:

NAVAL UNDERSEA CENTER SAN DIEGO CALIF

Personal Author(s):

• Benthien,George W.
• Nichols,Charles S.

Report Date:

1973-04-01

Pagination or Media Count:

45.0

Abstract:

Array gains of linear and rectangular arrays were calculated by summation of spatial-correlation coefficient over all pairs of array elements for a noise model consisting of a uniform distribution of dipoles on the surface of the sea. Approximate expressions for these array gains were derived for the same noise model. Calculated and approximate array gains were found to agree closely so long as the interelement spacing was not too small and there were no secondary major lobes. Calculated and approximate array gains for the surface dipole noise model were compared to those obtained for an isotropic noise model and were found to differ from them by as much as 10 dB, showing that the array gain is very sensitive to the type of noise environment in which the array is located.

Descriptors:

• *SONAR ARRAYS
• GAIN
• HYDROPHONES
• NOISE
• MATHEMATICAL MODELS
• APPROXIMATION(MATHEMATICS)

Subject Categories:

• Acoustic Detection and Detectors

Distribution Statement:

APPROVED FOR PUBLIC RELEASE